Adjuvant potential of low dose all-trans retinoic acid during oral typhoid vaccination in Zambian men.

There is an urgent need to identify ways of enhancing the mucosal immune response to oral vaccines. Rotavirus vaccine protection is much lower in Africa and Asia than in industrialized countries, and no oral vaccine has efficacy approaching the best systemic vaccines. All-trans retinoic acid (ATRA) up-regulates expression of α4ß7 integrin and CCR9 on lymphocytes in laboratory animals, increasing their gut tropism. The aim of this study was to establish the feasibility of using ATRA as an oral adjuvant for oral typhoid vaccination. In order to establish that standard doses of oral ATRA can achieve serum concentrations greater than 10 nmol/l, we measured ATRA, 9-cis and 13-cis retinoic acid in serum of 14 male volunteers before and 3 h after 10 mg ATRA. We then evaluated the effect of 10 mg ATRA given 1 h before, and for 7 days following, oral typhoid vaccine in eight men, and in 24 men given various control interventions. We measured immunoglobulin (Ig)A directed against lipopolysaccharide (LPS)and protein preparations of vaccine antigens in whole gut lavage fluid (WGLF) and both IgA and IgG in serum, 1 day prior to vaccination and on day 14. Median [interquartile range (IQR)] C(max) was 26·2 (11·7-39·5) nmol/l, with no evidence of cumulation over 8 days. No adverse events were observed. Specific IgA responses to LPS (P = 0·02) and protein (P = 0·04) were enhanced in WGLF, but no effect was seen on IgA or IgG in serum. ATRA was well absorbed, well tolerated and may be a promising candidate oral adjuvant.

Monitoring of early warning indicators for HIV drug resistance in antiretroviral therapy clinics in Zimbabwe.

Monitoring human immunodeficiency virus drug resistance (HIVDR) early warning indicators (EWIs) can help national antiretroviral treatment (ART) programs to identify clinic factors associated with HIVDR emergence and provide evidence to support national program and clinic-level adjustments, if necessary. World Health Organization-recommended HIVDR EWIs were monitored in Zimbabwe using routinely available data at selected ART clinics between 2007 and 2009. As Zimbabwe's national ART coverage increases, improved ART information systems are required to strengthen routine national ART monitoring and evaluation and facilitate scale-up of HIVDR EWI monitoring. Attention should be paid to minimizing loss to follow-up, supporting adherence, and ensuring clinic-level drug supply continuity.

Models for experimental infection of dogs fed with tissue from fetuses and neonatal cattle naturally infected with Neospora caninum.

Three models were designed to investigate the development and enteroepithelial phase of Neospora caninum in dogs, and to induce oocyst production by the parasite. In the first model, three dogs were fed raw fetal bovine tissue on two occasions. The bovine fetal tissue had been stored at 4 degrees C for 14 days and 16 days, respectively, and had tested positive for neosporosis using histopathology and immunohistochemistry. In the second model, nine dogs from the beginning of the experiment until euthanasia were fed portions of tissue from bovine fetuses that been stored at 4 degrees C for between 1 and 2 days. Three fetuses had tested positive for neosporosis using histopathology and immunohistochemistry. In the third model, three dogs were fed pieces of raw tissue from two neonatal calves that had not received colostrum, and which had tested positive for antibodies against N. caninum. The brains of these calves were positive for neosporosis by histopathology and immunohistochemistry. In all three models, none of the dogs excreted oocysts of N. caninum, developed intestinal parasites or seroconverted.

The effect of household poverty on tuberculosis.

pSETTING: Households in Malawi, Mongolia, Myanmar, the Philippines, Rwanda, Tanzania, Viet Nam and Zambia.OBJECTIVE To assess the relationship between household socio-economic level, both relative and absolute, and individual tuberculosis (TB) disease. DESIGN: We analysed national TB prevalence surveys from eight countries individually and in pooled multicountry models. Socio-economic level (SEL) was measured in terms of both relative household position and absolute wealth. The outcome of interest was whether or not an individual had TB disease. Logistic regression models were used to control for putative risk factors for TB disease such as age, sex and previous treatment history. RESULTS: Overall, a strong and consistent association between household SEL and individual TB disease was not found. Significant results were found in four individual country models, with the lowest socio-economic quintile being associated with higher TB risk in Mongolia, Myanmar, Tanzania and Viet Nam. CONCLUSIONS: TB prevalence surveys are designed to assess prevalence of disease and, due to the small numbers of cases usually detected, may not be the most efficient means of investigating TB risk factors. Different designs are needed, including measuring the SEL of individuals in nested case-control studies within TB prevalence surveys or among TB patients seeking treatment in health care facilities.

Plant diversity patterns in neotropical dry forests and their conservation implications.

Seasonally dry tropical forests are distributed across Latin America and the Caribbean and are highly threatened, with less than 10% of their original extent remaining in many countries. Using 835 inventories covering 4660 species of woody plants, we show marked floristic turnover among inventories and regions, which may be higher than in other neotropical biomes, such as savanna. Such high floristic turnover indicates that numerous conservation areas across many countries will be needed to protect the full diversity of tropical dry forests. Our results provide a scientific framework within which national decision-makers can contextualize the floristic significance of their dry forest at a regional and continental scale.

Reversal of severe neurological abnormalities after vitamin B12 replacement in the Imerslund-Grasbeck syndrome.

Vitamin B12 malabsorption in the ileum has been postulated as the underlying cause of the Imerslund-Grasbeck syndrome comprising megaloblastic anemia, proteinuria, and multiple neurological abnormalities. A young Saudi child with spasticity, truncal ataxia, cerebral atrophy, megaloblastic anaemia and proteinuria is described. Replacement therapy with parenteral vitamin B12 resulted in the complete resolution of his neurological findings and brain atrophy.

Surveillance of tuberculosis in Malawian prisons.

SETTING: The Malawi National Tuberculosis Programme (NTP) has collaborated with the Prison Health Services (PHS) on tuberculosis (TB) control in prisons since 1996. Information on case finding and treatment outcomes is routinely collected, but there has not been any recent countrywide review of these prison data. OBJECTIVES: To determine 1) the number of prisoners registered for TB in 2007, 2) TB treatment outcomes in 2006 and 3) training of prison health care staff in all Malawian prisons. DESIGN: Descriptive study involving a review of 2006 and 2007 data collected by the NTP during surveillance in 2008. RESULTS: In 2007, 278 TB patients were registered in Malawian prisons, representing a TB case notification rate of 835 per 100 000 (higher than that in the general population, at 346/100 000). The treatment success rate for new smear-positive TB cases for 2006 was 73%, lower than the national average of 78%. In all, 52 prison health care staff had received 1 week of training in TB management, usually just after starting work in the prison. CONCLUSIONS: TB case notifications in Malawian prisons were higher than in the general population and treatment outcomes less favourable. The NTP and PHS need better collaboration to improve TB control in Malawian prisons.

Prevalence of vitamin D deficiency in adult tuberculosis patients at a central hospital in Malawi.

Vitamin D deficiency (VDD) is associated with impaired mycobacterial immunity and susceptibility to tuberculosis (TB). We measured 25 hydroxy vitamin D levels in 161 adult TB patients at a central hospital in Malawi, of whom 120 (74.5%) had ≤75 nmol/l (hypovitaminosis D), 68 (42%) had ≤50 nmol/l (VDD) and 13.6% of in-patients and 6.8% of out-patients had ≤25 nmol/l (severe VDD). In-patients had lower body mass index (BMI; 19.0 vs. 20.5, P < 0.004), and vitamin D levels were lower in those with BMI < 20. However, on multiple regression analysis in-patient status and BMI were not associated with vitamin D level. We conclude that VDD is common in adult TB patients in Malawi. In this small sample, it was not possible to identify any independent associations of VDD.

Intravitreal injection of pegaptanib sodium for proliferative diabetic retinopathy.

BACKGROUND: To compare the efficacy of intravitreal pegaptanib (IVP) with panretinal laser photocoagulation (PRP) in the treatment of active proliferative diabetic retinopathy (PDR). METHODS: A prospective, randomised, controlled, open-label, exploratory study. Twenty subjects with active PDR were randomly assigned at a 1:1 ratio to receive treatment in one eye either with IVP (0.3 mg) every 6 weeks for 30 weeks or with PRP laser. Efficacy endpoints included regression of retinal neovascularisation (NV), changes from baseline in best-corrected visual acuity (BCVA) and foveal thickness. Safety outcomes included observed and reported adverse events. RESULTS: In 90% of randomised eyes to IVP, retinal NV showed regression by week 3. By week 12, all IVP eyes were completely regressed and maintained through week 36. In the PRP-treated group, at week 36, two eyes demonstrated complete regression, two showed partial regression, and four showed persistent active PDR. The mean change in BCVA at 36 weeks was +5.8 letters in pegaptanib-treated eyes and -6.0 letters in PRP-treated eyes. Only mild to moderate transient ocular adverse events were reported with pegaptanib. CONCLUSIONS: IVP produces short-term marked and rapid regression of diabetic retinal NV. Regression of NV was maintained throughout the study and at the final visit.

Comparison between immunohistochemistry and two PCR methods for detection of Neospora caninum in formalin-fixed and paraffin-embedded brain tissue of bovine fetuses.

The objective of this study was to identify the presence of the parasite by comparing immunohistochemistry (IHC) with two polymerase chain reaction (PCR) methods for the detection of the pNc5 gene and the internal transcribed spacer 1 (ITS1) of N. caninum in brain tissue of bovine fetuses that had previously been fixed in formalin and paraffin-embedded. In 29 out of 48 brains (60.4%), microscopic lesions consistent with Neospora infection were observed, and 21 of the 29 cases (72.41%) were positive for IHC. Fifteen of the 29 cases positive for IHC (51.72%) were also positive on the ITS1 PCR, and 12 cases were also positive on the pNc5 PCR (41.37%). The sensitivity of the PCR assays was 71.42% and 57.14%, respectively, and the specificity was 100% for both. The concordance between histopathology and IHC and the ITS1 PCR was 85%, and in the case of the pNc5 PCR it was 77.5%. When the number of fetuses positive by IHC and both PCR tests was compared, no statistically significant difference was found (P>0.05). It is concluded that the use of formalin-fixed and paraffin-embedded bovine fetal tissues allows the detection of N. caninum by IHC or PCR. Nevertheless, it is recommended that more than one technique is used to increase the diagnostic sensitivity, and preferably tests that show better performance in the individual laboratory should be selected.

Three M components IgA lambda, + IgG kappa n + IgG kappa h in one patient. II. Structurally different kappa n and kappa h chains associated with H(gamma) chains sharing idiotypic determinants.

Structural analysis of purified IgG kappa h and IgG kappa n molecules of DA myeloma paraproteins indicated that the two IgG had different electrophoretic mobility and that L-kappa h had an unusually heavy m.w. (30,000). Peptide mapping showed the existence of additional peptides in the L-kappa h map when compared to the L-kappa n map. Total amino acid analysis showed that L-kappa h contained two additional cysteine residues and certain other amino acids than L-kappa n contained. Sequence of the first 25 NH2-terminal amino acids showed differences at positions 4, 5, 15, 18, and 21, but both L-kappa h and L-kappa n belong to the same V kappa IV subgroup. IgG kappa n but not IgG kappa h reacted with anti-gamma 1 antiserum, indicating that H chains of these two paraproteins were also different. Sera from rabbits immunized with IgG kappa n or IgG kappa h, and rendered specific for idiotypic determinants by appropriate absorption, were used for idiotype characterization of these components. Immunodiffusion, immunoelectrophoresis, and direct hemagglutination demonstrated that IgG kappa h and IgG kappa n cross-reacted partially. Inhibition tests disclosed that the main anti-idiotypic antibody was directed against a conformation structure of the complete IgG kappa h molecule, whereas cross-reaction was due to partial idiotypic similarity between H chains of the IgG kappa h and IgG kappa n. In addition, each of these paraproteins seemed also to bear private idiotypes on their H and L chains.

Three M-components IgA lambda + IgG kappa n + IgG kappa h in one patient (DA): lack of shared idiotypic determinants between IgA and IgG, and the presence of an unusual kappa h chain of 30,000 M.W.

Two apparently homogeneous electrophoretic bands were found in the serum of a patient (DA) with multiple myeloma. These M-components were identified as IgA-lambda and IgG-kappa paraproteins bearing different idiotypic determinants. Further analysis of the L chains showed that the lambda-chain was homogeneous but the kappa-chain could be separated by SDS-polyacrylamide gel electrophoresis into two different bands. Both of them were associated with gamma-chains but one (termed kappa n) had normal m.w. (24,500) whereas the other (termed kappa h) was larger (m.w. 30,000). Sugar content of the two DA IgG, as determined by anthrone reaction, was similar in DA IgG kappa n (0.73%) and in DA IgG kappa h (1.1%), clearly demonstrating that the difference in m.w. was not due to a large sugar chain. Furthermore, the peptide map of the kappa h chain included nine peptides absent in those of four other control kappa-chains. Sequence analysis showed that the first 25 N-terminal amino acids of the kappa n differed from those of the kappa h chain at positions 4, 5, 15, 18, and 21. Thus the two kappa-chains had different framework regions.

Surgical bacterial infections and antimicrobial susceptibility patterns at Lilongwe Central Hospital.

A cross sectional study was done between October 1999 and February 2000 to determine antimicrobial susceptibility patterns of consecutive bacterial isolates of 102 clinical samples among surgical in-patients at Lilongwe Central Hospital (LCH), Malawi. Antimicrobial susceptibility was determined using comparative disc diffusion techniques. 83 (81.4%) samples were culture positive for bacterial growth while 19 (18.6%) grew nothing. Of the 93 culture positive specimens, Staphylococcus aureus was the predominant organism 43(51.8%) followed by Proteus species 8(9.6%) and E. coli 7(8.4%). Overall, 98.6% of all isolates tested against ciprofloxacin were susceptible, and against gentamicin and flucloxacin were 84.8% and 66.7% respectively. 59.3% of isolates tested against chloramphenicol were resistant. We recommend a review on the use of chloramphenicol as first-line antimicrobial therapy among surgical in-patients at Lilongwe Central Hospital. We also recommend restricted use of antimicrobials so as to minimise development of drug resistance. Periodic susceptibility studies are necessary to guide judicious use of antibiotics.